Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1343—Electrodes
  • G02F1/134309—Electrodes characterised by their geometrical arrangement
  • G02F1/134363—Electrodes characterised by their geometrical arrangement for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/133553—Reflecting elements
  • G02F1/133555—Transflectors
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
  • G02F1/133707—Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F2203/00—Function characteristic
  • G02F2203/09—Function characteristic transflective

Definitions

• the present invention relates to a display device. More specifically, the present invention relates to a display device suitably used for liquid crystal display in an in-plane switching (IPS) mode or a fringe field switching (FFS) mode.
• IPS in-plane switching
• FFS fringe field switching
• Display devices such as liquid crystal display devices are widely used in electronic devices such as monitors, projectors, mobile phones, and personal digital assistants (PDAs).
• Examples of the display mode of the liquid crystal display device include a reflection type, a transmission type, and a reflection / transmission type.
• transmissive liquid crystal display devices that use the light of knocklights are mainly used in indoor and other relatively dark environments, and mainly ambient light is used in relatively bright environments such as outdoors.
• the reflective liquid crystal display device used is used.
• the reflective / transmissive liquid crystal display device can perform both transmissive display and reflective display, and can mainly display transmissive display indoors and can mainly display reflective display outdoors.
• a vertical alignment (VA) mode is used as a display mode.
• liquid crystal molecules are aligned perpendicularly to the substrate surface when the applied voltage is off, and display is performed by tilting the liquid crystal molecules when the applied voltage is on.
• the reflected light is transmitted through the liquid crystal layer twice.
• the transmitted light is transmitted through the liquid crystal layer once and does not pass through the force.
• the light transmittance is about 1Z2 which is the optimum value.
• a method of forming a multi-gap structure in which the cell gap is different between the reflective region and the transmissive region and reducing the thickness of the liquid crystal layer in the reflective region is disclosed (for example, (Refer to Patent Document 1.)
• this method since it is necessary to provide a concavo-convex structure on the substrate, the structure becomes complicated and high accuracy is required in the manufacturing process. There is room for further improvement. There is also room for improvement in that the response time of liquid crystal molecules differs between the reflective region and the transmissive region.
• an IPS mode and an FFS mode are known.
• the liquid crystal is operated by a horizontal electric field from a pair of electrodes for driving the liquid crystal provided on one substrate to perform display.
• the liquid crystal molecules are rotated in the horizontal direction (substrate parallel direction), so that the viewing angle can be increased.
• a reflection / transmission type liquid crystal display device is disclosed (for example, see Patent Document 2), but this also has a multi-gap structure and does not solve the above-described problem.
• Patent Document 1 Japanese Patent Laid-Open No. 11-242226
• Patent Document 2 JP 2005-338264 A
• the present invention has been made in view of the above-described situation, and can provide bright and display in both the reflective display and the transmissive display without providing a multi-gap structure, and the reflective area and the transparent area. It is an object of the present invention to provide a display device that can reduce the difference in response time between the two.
• the present inventor has made various studies on a display device that can clearly display both the reflective display and the transmissive display without providing a multi-gap structure. Attention was paid to the positional relationship between the pixel electrode and the common electrode. Even without providing a multi-gap structure, a horizontal electric field method such as IPS mode or FFS mode is adopted, a plurality of slits are provided in the pixel electrode, and at least one of these slits is a line-symmetrical slit. Further, a slit is provided between the line-symmetric slits, and the inner contour line facing the line-symmetric slit is a line such that one contour line has an angle with respect to the other contour line.
• the strength of the electric field generated between the pixel electrode and the common electrode can be made weaker in the reflective region than in the transmissive region.
• the present invention includes a pair of substrates and a display medium sandwiched between the substrates, and a reflective region for performing reflective display and a transmissive region for performing transmissive display are formed in the pixel.
• the display device includes a pixel electrode and a common electrode on one of the substrates, and applies a voltage to the display medium by the pixel electrode and the common electrode.
• a plurality of slits, and the plurality of slits includes at least one pair of line-symmetrical slits and slits provided between the line-symmetrical slits, and are opposed to the line-symmetrical slits.
• the inner contour line is such that one contour line has an angle with respect to the other contour line, and the axis of symmetry of the line symmetry is also referred to as a display device (hereinafter also referred to as a first display device). ).
• a first display device of the present invention includes a pair of substrates and a display medium sandwiched between the substrates, and a reflective area for performing reflective display and a transmissive area for performing transmissive display in a pixel. And are formed.
• the type of the substrate and the type of the display medium are not particularly limited.
• the scanning wiring and the signal wiring are arranged on the substrate so as to intersect with each other.
• An example is a mode in which a liquid crystal layer sandwiched between substrates is provided as a display medium. Further, in a liquid crystal display device, a polarizing plate, a backlight, etc. are usually provided outside these.
• the reflective display is a method of performing display by reflecting ambient light or light emitted from a front light provided on the display surface side in the display device.
• the transmissive display is a method of performing display by transmitting light emitted from the backlight.
• the size of the reflective region and the transmissive region and the proportion of them in the pixel are not particularly limited. Since the present invention has a reflective region and a transmissive region in one pixel, it is a reflective / transmissive display device.
• the display device of the present invention includes a pixel electrode and a common electrode on one side of a substrate, and applies a voltage to a display medium through the pixel electrode and the common electrode.
• Pixel electrode and common power When a voltage is applied to an electrode pair composed of electrodes, a lateral electric field parallel to the substrate is generated in the display medium adjacent to the pixel electrode and the common electrode. This electric field controls the display medium.
• the pixel electrode and the common electrode have a so-called comb-tooth shape, and are provided in the same layer so that these electrodes are engaged with each other (IPS Method), pixel electrodes or common electrodes are comb-like, and these electrodes are provided in different layers (FFS method).
• the pixel electrode is provided with a plurality of slits.
• the plurality of slits includes at least one set of line-symmetric slits and slits provided between the line-symmetric slits. That is, among a plurality of slits, there are at least one set of two slits having a line-symmetric shape with a virtual line as an axis of symmetry, and another slit between the pair of line-symmetric slits. Exists.
• the number of slits provided between a set of axisymmetric slits may be singular or plural.
• the line symmetry is only required to be substantially line symmetrical to such an extent that the effects of the present invention can be obtained. Note that the number of such line-symmetrical combinations usually requires the number of combinations that can form a reflective region.
• the opposite inner contour lines of the line-symmetrical slit have an angle with respect to the other contour line.
• the shape of each of the line-symmetric slits formed at this time is a line other than the parallel lines between the opposing inner contour lines. Therefore, for example, the shape in which the opposing inner contour lines are parallel to each other, such as when a rectangle or a square is arranged in parallel, may be a force that is excluded from the present invention.
• the slit provided between the set of line-symmetrical slits can be easily made wider than the slit formed in the other region. As the slit width increases, the electric field strength between the pixel electrode and the common electrode decreases.
• the degree of alignment of the liquid crystal changes depending on the strength of the electric field, the utilization efficiency of light transmitted through the liquid crystal can be adjusted using this.
• the line-symmetric axis of symmetry is located in the reflection region.
• the slit that is the axis of symmetry of the line-symmetrical slit and Z or the vicinity thereof are provided with slits that are easier and wider than the slits provided in the area unless they are other axis of symmetrical symmetry of the line. Therefore, the region where the slit is provided and z or its vicinity are used as the reflection region. be able to.
• the slit width of the pixel electrode formed in the reflective region is not particularly limited as long as it is greater than the average slit width of the pixel electrode formed in the transmission region. For example, the slit width is formed in the reflective region.
• a part of the slit width of the pixel electrode may have a portion approximately the same as the slit width of the pixel electrode formed in the transmission region.
• the maximum value of the slit width of the pixel electrode formed in the reflective region is larger than the maximum value of the slit width of the pixel electrode formed in the transmissive region.
• a preferred form of the pixel electrode includes, for example, a comb-like form.
• a comb-teeth shape By adopting a comb-teeth shape, a lateral electric field can be formed with high density between the pixel electrode and the common electrode, and the display medium can be controlled with high accuracy.
• the comb-teeth shape refers to a shape in which one long line force and a plurality of short lines protrude, and the shape of one comb tooth is not particularly limited.
• Preferable forms of the slit formed in the pixel electrode include, for example, a form in which the entire periphery is surrounded by the pixel electrode, a form in which the rectangle is bent at least once, and a zigzag form Examples include forms, arcuate forms, and meandering forms. According to such a configuration, the pixel electrode and the common electrode can be efficiently meshed with each other, whereby a lateral electric field can be formed with high density, and the display medium can be controlled with high accuracy. It becomes.
• a preferred form of the common electrode is a form in which the common electrode is provided in a layer different from the pixel electrode with an insulating film interposed therebetween.
• the FFS system in which the pixel electrode and the common electrode are arranged with an insulating film interposed therebetween, a horizontal electric field parallel to the substrate can be generated in the display medium.
• Examples of such a form include a case where one electrode has a comb-like shape and the other electrode force S has a flat shape without a slit.
• the present invention can be applied even when the pixel electrode and the common electrode cannot be provided in the same layer due to restrictions such as the aperture ratio.
• the line-symmetric axis of symmetry is preferably located in a slit provided between the line-symmetric slits.
• the distance between the pixel electrodes located on both sides of the slit can be easily increased.
• the power generated between the pixel electrode and the common electrode Can effectively weaken the strength of the world.
• the common electrode is a form in which a slit is provided.
• the common electrode is preferably provided in a layer where the pixel electrode is formed.
• the common electrode is also provided with slits, interlaced with the pixel electrode slits, and the pixel electrode and common electrode are arranged in the same layer. An electric field can be generated. Further, since the manufacturing process can be simplified by forming the pixel electrode and the common electrode in the same layer, productivity is improved.
• the slit of the common electrode preferably includes substantially the same shape as the slit of the pixel electrode. By doing so, the strength of the electric field generated in each part where the slits of the common electrode and the slits of the pixel electrode are interlaced can be made uniform, and the alignment of the liquid crystal can be controlled uniformly.
• the common electrode may have substantially the same shape as a pair of line-symmetrical slits of the pixel electrode. By providing the slit so as to be adjacent to the set of line-symmetrical slits, the interval between the pixel electrode and the common electrode can be efficiently increased in the reflective region.
• “same” means that the strength of the electric field generated in each part can be made substantially uniform (so as not to affect the display quality). Say something.
• the common electrode and the pixel electrode are positioned in the respective slits. That is, the common electrode is located in the slit of the pixel electrode, and the pixel electrode is located in the slit of the common electrode.
• the slits of the common electrode and the slit of the pixel electrode substantially the same shape, an electrode pair in which the pixel electrode and the common electrode are alternately sandwiched can be formed. The lateral electric field parallel to the substrate can be generated more uniformly and with high density.
• the line-symmetric axis of symmetry is preferably located within the slit of the common electrode.
• the pixel electrode is shared in the reflection region.
• a shield electrode is provided between the electrode and the electrode.
• the term “shield electrode” refers to an electrode that is interposed between a pixel electrode and a common electrode and changes a potential difference between the pixel electrode and the common electrode. Since the shield electrode is provided between the pixel electrode and the common electrode, a potential difference generated between the pixel electrode and the common electrode is smaller than that in the case where the shield electrode is not provided. By combining them, the strength of the electric field generated between the pixel electrode and the common electrode can be reduced more effectively in the reflective region than in the transmissive region.
• the material of the shield electrode is not particularly limited as long as it has conductivity, but a material having translucency is particularly preferable.
• a metal oxide such as indium tin oxide (ITO) is preferably used.
• ITO indium tin oxide
• the shield electrode can be provided between the pixel electrode and the common electrode, the size and shape thereof are not particularly limited.
• the shield electrode is preferably grounded. By grounding, the voltage applied to the shield electrode can be kept constant at 0V. By grounding the shield electrode and setting the shield electrode potential to 0V, the potential difference between the pixel electrode and the common electrode can be effectively reduced.
• the present invention also includes a pair of substrates and a display medium sandwiched between the substrates, and a reflective region for performing reflective display and a transmissive region for performing transmissive display are formed in the pixel.
• the display device includes a pixel electrode and a common electrode on one of the substrates, and applies a voltage to the display medium by the pixel electrode and the common electrode, and the common electrode includes a plurality of common electrodes.
• the plurality of slits are configured to include at least one set of line-symmetric slits and slits provided between the line-symmetric slits, and the inner sides of the line-symmetric slits are opposed to each other.
• the one contour line is angled with respect to the other contour line, and the axis of symmetry of the line symmetry is also a display device (hereinafter also referred to as a second display device) located in the reflection region. . That is, the pixel electrode in the first display device is replaced with a common electrode, and the common electrode is replaced with a pixel electrode.
• the second display device of the present invention having a feature in the slit of the common electrode can also achieve the same effect as the first display device of the present invention having a feature in the slit of the pixel electrode.
• a preferred form of the common electrode is a comb-like shape.
• preferable forms of the slit formed in the common electrode include a form in which the entire periphery is surrounded by the common electrode, a form in which the rectangle is bent at least once, a form in which the zigzag shape is formed, and an arc shape Examples include forms and meandering forms.
• Another preferable form of the common electrode is a form provided in a layer different from the pixel electrode with an insulating film interposed therebetween.
• a preferred form of the pixel electrode is a form in which a slit is provided.
• the slit formed in the pixel electrode As a preferable form of the slit formed in the pixel electrode, a form in which the slit of the pixel electrode includes substantially the same shape as the slit of the common electrode can be mentioned.
• a preferred form of the second display device is a form in which a shield electrode is provided between the common electrode and the pixel electrode in the reflective region. At this time, the shield electrode is preferably grounded.
• the display device of the present invention it is possible to perform bright display in both reflective display and transmissive display without providing a multi-gap structure.
• it is not necessary to provide a multi-gap structure it is possible to reduce the occurrence of a difference in response time of liquid crystal molecules between the reflective region and the transmissive region.
• Embodiment 1 is a liquid crystal display device that has an IPS mode configuration in the first display device or the second display device of the present invention.
• FIG. 11 is a schematic plan view of one pixel constituting the liquid crystal display device of Embodiment 1
• FIG. 11 is a schematic cross-sectional view taken along a broken line AB shown in FIG. 1-1.
• the liquid crystal display device of Embodiment 1 includes a first substrate 1, a second substrate 2, and a liquid crystal layer 3 sandwiched between these substrates, as shown in FIG.
• the second substrate 2 includes a pixel electrode 4 and a common electrode 5, and a voltage is applied to the liquid crystal layer 3 by the pixel electrode 4 and the common electrode 5.
• the first substrate 1 has a color filter layer 6 and a first alignment film 7 in this order on the liquid crystal layer 3 side.
• a glass substrate can be used as the first substrate 1.
• regions exhibiting red, green, and blue are repeatedly arranged.
• the color filter layer 6 may be composed of areas of four colors or more.
• the unevenness caused by the color filter layer 6 may be flattened with a flat resin layer made of resin.
• the first alignment film 7 defines the alignment direction of the adjacent liquid crystal layer 3.
• the second substrate 2 has, on the liquid crystal layer 3 side, the scanning wiring 8, the common wiring 9, the first insulating layer 10, the signal wiring 11, the thin film transistor 12, the second insulating layer 13, the reflector 14, Three insulating layers 15, a pixel electrode 4 and a common electrode 5, and a second alignment film 16 are provided.
• a glass substrate can be used similarly to the first substrate 1.
• the scanning wiring 8 and the signal wiring 11 are formed in different layers via the first insulating layer 10 and are orthogonal to each other.
• the thin film transistor 12 is located in the vicinity of the intersection between the scanning wiring 8 and the signal wiring 11.
• the structure is an inverted staggered structure, the gate electrode is connected to the scanning wiring 8, the source electrode is connected to the signal wiring 11, and the drain electrode is connected to the pixel electrode 4 through the first contact hole 17. It is.
• the channel portion of the thin film transistor 12 is formed of an amorphous silicon layer.
• the common wiring 9 is provided in parallel with the scanning wiring 8, and the common electrode 5 is connected through the second contact hole 18.
• Each of the pixel electrode 4 and the common electrode 5 has a comb shape, and the comb teeth (projections) are formed in an arc shape.
• the pixel electrode 4 and the common electrode 5 are made of indium tin oxide (ITO). Oxide) is a transparent electrode formed in the same layer. For this reason, the manufacturing process can be simplified compared to the case where the layers are formed in different layers.
• ITO indium tin oxide
• Oxide Oxide
• a horizontal electric field is formed in the liquid crystal layer 3 and an alignment change occurs. As a result, control of light transmitted through the liquid crystal layer 3 is performed.
• the region overlapping with the reflector 14 is the reflection region R, and FIG.
• the portion shown in black in 1 is the reflection region R. As shown in FIG. 12, the reflected light 20 passes through the reflection region R. The transmitted light 21 from the knock light is transmitted through the transmission region T.
• the material of the reflection plate 14 aluminum or silver alloy having high reflectivity is suitable.
• the force using the pixel electrode 4 and the common electrode 5 made of the same material in the transmission region T and the reflection region R is provided with a plurality of slits in the pixel electrode 4 and the common electrode 5, respectively. Some of them are a combination of arcuate line-symmetric slits. In addition, another slit is provided between each line-symmetrical slit combination.
• a reflection region R is formed in a region between the comb teeth of the pixel electrode 4 and the comb teeth of the common electrode 5 including the symmetry axis of a set of line-symmetric slits of the pixel electrode 4.
• each of the comb teeth of the pixel electrode 4 and the common electrode 5 of Embodiment 1 has an arc shape.
• the pixel electrode 4 and the common electrode 5 have arcs facing each other across the reflection region R.
• the pixel electrode 4 and the common electrode 5 have a shape in which the arcs are arranged side by side in the same direction.
• the reflection region R is formed between the comb teeth of the pixel electrode 4 and the comb teeth of the common electrode 5 whose arcs face each other.
• the symmetry axis of the pair of line-symmetric slits of the pixel electrode 4 is located in the slit provided between the line-symmetric slits, and is within the slit of the common electrode 5. Will be located.
• the slits of the common electrode 5 have substantially the same shape as the slits of the pixel electrode 4, and the common electrode 5 and the pixel electrode 4 are located in the respective slits. In other words, in this embodiment, the comb teeth of the pixel electrode 4 and the comb teeth of the common electrode 5 are evenly mixed.
• the slit widths of the pixel electrode 4 and the common electrode 5 in the reflection region R are wider than the slit widths of the pixel electrode 4 and the common electrode 5 in the transmission region T. Even if the pixel electrode 4 and the common electrode 5 are used, the voltage applied to the liquid crystal layer 3 is different between the transmissive region T and the reflective region R. Reflective display and transmissive display can be performed without changing the thickness of 3 (multi-gap).
• a second alignment film 16 is further provided on the liquid crystal layer 3 side of the pixel electrode 4, and the alignment direction is defined close to the liquid crystal layer 3.
• the slit width of the pixel electrode 4 in the reflective region R is the same as the slit width of the pixel electrode 4 in the transmissive region T in the minimum region, and the slit in the transmissive region T in the strongest region. It is more than twice the width. Further, the average slit width of the pixel electrode 4 in the reflective area is larger than the average slit width of the pixel electrode 4 in the transmissive area T. Therefore, according to the present embodiment, the effects of the present invention can be sufficiently achieved.
• the shape and arrangement of the pixel electrode 4 and the common electrode 5 are not limited to those shown in FIG. 11 and may be, for example, the shapes and arrangements shown in FIGS.
• the pixel electrode 4 and the common electrode 5 shown in FIG. 2 are different from those shown in FIG. 11, and the common electrode 5 is symmetrical with a set of arc-symmetrical slits formed in the pixel electrode 4. It is formed with straight comb teeth on the shaft.
• the pixel electrode 4 has a shape in which the arcs face each other, and a reflection region R is formed between the comb teeth of the pixel electrodes 4 facing each other, including the symmetry axis of the line-symmetric slit.
• the axis of symmetry of the arc-shaped set of line-symmetric slits formed in the pixel electrode 4 is not located within the slit of the common electrode 5 1S Even in such an arrangement, the pixel electrode 4 in the reflective region R Therefore, the reflection region R is a region including the symmetry axis of a pair of line-symmetric slits provided in the pixel electrode 4 because the slit width of the reflection region R is wider than the slit width of the pixel electrode 4 in the transmission region T. Can be formed.
• the pixel electrode 4 and the common electrode 5 shown in FIG. 3 are similar to those in FIG.
• the pole 4 and the common electrode 5 are shaped so as to be held together by an arc.
• the degree of arc curvature of the pixel electrode 4 and the common electrode 5 is small.
• the reflection region R is not only between the regions where the center of the comb teeth of 5 extends but also between the regions where the center of the comb teeth of the pixel electrode 4 and the center of the comb teeth of the common electrode 5 narrow. It is provided. As shown in Fig.
• the reflection region R is set even in a region where the center of the comb teeth of the pixel electrode 4 and the center of the comb teeth of the common electrode 5 are narrowed to each other.
• the reflection region R is a region where the pixel electrode 4 and the common electrode 5 face each other, including the symmetry axis of the line-symmetric slit formed in the pixel electrode 4. It is included in the present invention. According to such an arrangement, the distance between the pixel electrode 4 and the common electrode 5 becomes wider as it goes to the root of the comb teeth, so that this region can be used as the reflection region R.
• the pixel electrode 4 shown in FIG. 4 is formed by linear comb teeth of the pixel electrode 4 on the symmetry axis of a set of arc-symmetrical slits formed in the pixel electrode 4.
• the common electrode 5 is formed by linear comb teeth of the common electrode 5 on the axis of symmetry of the line-symmetric slit formed in the common electrode 5.
• a reflection region R is formed between the comb teeth of the pixel electrodes 4 facing each other including the axis of symmetry of these line-symmetric slits. That is, the symmetry axis of the arc-shaped set of line-symmetric slits formed on the pixel electrode 4 is not located in the slit provided between the set of line-symmetric slits.
• the slit width of the pixel electrode 4 in the reflective region R is wider than the slit width of the pixel electrode 4 in the transmissive region T. Therefore, the reflective region R is a set of pixels provided in the pixel electrode 4. It can be formed in a region including the symmetry axis of the line-symmetric slit.
• FIG. 5 shows the positional relationship between the polarizing plate, the phase difference plate, and the liquid crystal molecules when no voltage is applied.
• Figure 6 shows the positional relationship between the polarizing plate, the phase difference plate, and the liquid crystal molecules in the reflection region when a voltage is applied.
• Figure 7 shows the positional relationship between the polarizing plate, the phase difference plate, and the liquid crystal molecules in the transmission region when a voltage is applied.
• Embodiment 1 as shown in FIG. 12, the side opposite to the liquid crystal layer 3 of the first substrate 1, and The first polarizing plate 22 and the second polarizing plate 23 are arranged on the opposite side of the second substrate 2 with respect to the liquid crystal layer 3 so that the transmission axes 26 and 27 are orthogonal to each other.
• a first retardation plate 24 is disposed between the first substrate 1 and the first polarizing plate 22, and the second retardation plate 24 is disposed between the second substrate 2 and the second polarizing plate 23.
• Two retardation plates 25 are arranged.
• the phase difference of the first retardation plate 24 is set to a quarter wavelength, and its slow axis 28 is rotated 45 clockwise with respect to the alignment direction of the liquid crystal molecules 30.
• the transmission axis 26 of the first polarizing plate 22 is set to be parallel to the alignment direction of the liquid crystal molecules 30.
• the phase difference of the second retardation plate 25 is set to a quarter wavelength, and its slow axis 29 is arranged so as to be orthogonal to the slow axis 28 of the first retardation plate 24.
• the laminate of the liquid crystal layer 3, the first polarizing plate 22, and the first retardation plate 24 is It functions as a circularly polarizing plate.
• the linearly polarized light transmitted through the first polarizing plate 22 becomes circularly polarized light when transmitted through the first retardation plate 24.
• it becomes circularly polarized light in the direction opposite to that at the time of incidence, and when entering the first polarizing plate 22 again, the vibration direction is directed to the transmission axis 26 of the first polarizing plate 22.
• the first phase difference plate 24 and the second phase difference plate 25 are orthogonal to each other. Therefore, the phase difference viewed from the normal direction of the first substrate 1 is zero, and this direction It does not affect the display when viewed from above.
• the voltage applied to the pixel electrode 4 and the common electrode 5 is less than the threshold value, the long axis of the liquid crystal molecules 30 is orthogonal to the transmission axis 27 of the second polarizing plate 23.
• the transmitted linearly polarized light is linearly polarized light perpendicular to the transmission axis 26 of the first polarizing plate 22, and is thus absorbed by the first polarizing plate 22 to obtain a dark display.
• the liquid crystal molecules 30 change the orientation by a predetermined angle 2 ⁇ clockwise as shown in FIG. Incident on first polarizing plate 22
• the vibration direction is linearly polarized light parallel to the transmission axis 26 of the first polarizing plate 22, it is not absorbed by the first polarizing plate 22 and a bright display is obtained.
• the first retardation plate 24 and the second retardation plate 25 are materials having a low refractive index wavelength dispersion.
• the reflection / transmission liquid crystal display panel manufactured as described above is connected to a driving device, and a backlight is disposed behind the device, thereby completing the reflection / transmission liquid crystal display device.
• the shape of the comb teeth (protrusions) in the comb-like pixel electrode 4 and the common electrode 5 is not limited to the arc shape as shown in FIG. 11, for example, as shown in FIGS. It may be a simple shape.
• the comb-shaped electrode 31 shown in FIG. 8 has a V-shape bent once in a polygonal line at the center of the comb teeth, and the slit shape is a shape in which a rectangular slit is bent once.
• the comb-teeth have two bent line-shaped bent portions, and as a whole have a substantially V-shape, and the slit shape is a rectangular slit bent twice. It is a shape.
• the comb-teeth electrode 33 shown in FIG. 10 has a shape in which the comb-teeth have three bent line-shaped bent portions, and generally have two V-shaped portions, and the slit shape is a rectangular shape. It has a zigzag shape with slits bent three times.
• the comb-like electrode 34 shown in FIG. 11 the comb-teeth have three arc-shaped curved portions, and as a whole, have a shape in which approximately two V-shapes are arranged, and the slits meander.
• the regions that are the symmetry axes of a set of line-symmetric slits are reflection regions R, as shown in FIGS.
• FIG. 12 is a schematic diagram showing the pixel electrode 4 and the common electrode 5 of the first embodiment.
• FIG. 12 (a) is a schematic plan view of the pixel electrode 4 and the common electrode 5, and (b), (c), and (d) are three schematic cross-sectional views of a broken line CD shown in (a).
• the arrangement relationship between the pixel electrode 4 and the common electrode 5 is not limited to the form in which the pixel electrode 4 and the common electrode 5 are formed in the same layer as shown in FIG. 12 (b), and as shown in FIG.
• the common electrode 5 may be formed on the liquid crystal layer 3 side of the pixel electrode 4 as shown in FIG. 12 (d).
• FIG. 13 is a schematic diagram when the shield electrode 50 is provided between the pixel electrode 4 and the common electrode 5 of the first embodiment.
• FIG. 13 (a) is a schematic plan view
• FIG. 13 (b) is a schematic cross-sectional view taken along the broken line CD in FIG. 13 (a). Even if the shield electrode 50 is provided between the pixel electrode 4 and the common electrode 5, the strength of the electric field generated between the pixel electrode 4 and the common electrode 5 can be reduced.
• the shield electrode 50 is preferably grounded.
• Embodiment 2 is a liquid crystal display device in which the first display device or the second display device of the present invention has an FFS mode configuration.
• FIG. 141 is a schematic plan view of one pixel constituting the liquid crystal display device of Embodiment 2.
• FIG. 142 is a schematic cross-sectional view taken along broken line EF shown in FIG. 14-1.
• the liquid crystal display device of Embodiment 2 includes a first substrate 101, a second substrate 102, and a liquid crystal layer 103 sandwiched between these substrates.
• the second substrate 102 includes a pixel electrode 104 and a common electrode 105, and a voltage is applied to the liquid crystal layer 103 by the pixel electrode 104 and the common electrode 105.
• the first substrate 101 has a color filter layer 106 and a first alignment film 107 in this order on the liquid crystal layer 103 side.
• a glass substrate can be used as the first substrate 101 .
• regions exhibiting red, green, and blue are repeatedly arranged.
• the color filter layer 106 may be composed of regions of four or more colors.
• the unevenness caused by the color filter layer 106 may be flattened with a flat resin layer made of resin.
• the first alignment film 107 defines the alignment direction of the adjacent liquid crystal layer 103.
• the second substrate 102 has a scanning wiring 108, a common wiring 109, a first insulating layer 110, a signal wiring 111, a thin film transistor 112, a second insulating layer 113, a reflector 114, and a first wiring on the liquid crystal layer 103 side.
• a third insulating layer 115, a common electrode 105, a fourth insulating layer 119, a pixel electrode 104, and a second alignment film 116 are provided.
• a glass substrate can be used in the same manner as the first substrate 101.
• the scanning wiring 108 and the signal wiring 111 pass through the first insulating layer 110. Are formed in different layers and are orthogonal.
• the thin film transistor 112 is located in the vicinity of the intersection between the scanning wiring 108 and the signal wiring 111.
• the structure is an inverted staggered structure, the gate electrode is connected to the scanning wiring 108, the source electrode is connected to the signal wiring 111, and the drain electrode is connected to the pixel electrode 104 through the first contact hole 117. ing.
• the channel portion of the thin film transistor 112 is formed of an amorphous silicon layer.
• the common wiring 109 is provided in parallel with the scanning wiring 108 and is connected to the common electrode 105 through the second contact hole 118.
• the pixel electrode 104 has a comb shape, and the comb teeth (projections) are formed in an arc shape.
• the common electrode 105 is formed over the entire pixel, and is positioned below the pixel electrode 104, separated by the fourth insulating layer 119.
• the pixel electrode 104 and the common electrode 105 are transparent electrodes made of indium stannate (ITO).
• ITO indium stannate
• the region overlapping with the reflector 114 is the reflection region R, and the black portion in FIG. 14-1 is the reflection region R.
• the reflected light 120 passes through the reflection region R.
• the transmitted light 121 from the knock light is transmitted through the transmission region T.
• the material of the reflector 114 aluminum or silver alloy having high reflectivity is suitable.
• the pixel electrode 104 and the common electrode 105 that use the same material in the transmissive region T and the reflective region R are provided with a plurality of slits, and some of them are provided. Is a combination of arcuate line-symmetric slits. Further, another slit is provided between the combinations of the line-symmetric slits. Then, a reflection region R is formed in a region between the comb teeth of the pixel electrode 104 and the adjacent comb teeth of the pixel electrode 104 including the symmetry axis of the pair of line-symmetric slits of the pixel electrode 104. ing.
• each of the comb teeth of the pixel electrode 104 of Embodiment 2 has an arc shape. Then, in the part that becomes the reflection region R, the comb teeth of the pixel electrode 104 sandwich the reflection region R. The arcs face each other. On the other hand, in the region that becomes the transmission region T, the arcs are arranged side by side in the same direction. According to the present embodiment, the pixel electrode
• the symmetry axis of the pair of line-symmetric slits 104 is located in a slit provided between the line-symmetric slits.
• the slit width of the pixel electrode 104 in the reflection region R is wider than the slit width in the transmission region T, and the liquid crystal layer 103 is provided with a step-forming layer separately in the reflection region R. Reflective display and transmissive display can be performed without changing the thickness of the display (multi-gap).
• a second alignment film 116 is further provided on the liquid crystal layer 103 side of the pixel electrode 104, and the alignment direction is defined in the vicinity of the liquid crystal layer 103.
• the common electrode 105 is provided in a layer different from the pixel electrode 104 with an insulating film interposed therebetween.
• the slit width of the pixel electrode 104 in the reflection region R is the same as the slit width of the pixel electrode 104 in the transmission region T in the minimum region, and the slit width in the transmission region T in the maximum region. It is more than twice the width. Further, the average slit width of the pixel electrode 104 in the reflection region R is larger than the average slit width of the pixel electrode 104 in the transmission region T. Therefore, according to the present embodiment, the effects of the present invention can be sufficiently achieved.
• the arrangement relationship of the polarizing plate, the retardation plate, and the liquid crystal molecules of Embodiment 2 is the same as that of Embodiment 1, and the opposite side of the first substrate 101 from the liquid crystal layer and the second substrate 102.
• the first polarizing plate 122 and the second polarizing plate 123 are arranged so that their transmission axes are orthogonal to each other.
• a first retardation plate 124 is disposed between the first substrate 101 and the first polarizing plate 122, and a second retardation plate 124 is disposed between the second substrate 102 and the second polarizing plate 123.
• the phase difference plate 125 is arranged.
• the retardation of the first retardation plate 124 is set to a quarter wavelength, and the slow axis is set to 45 degrees clockwise with respect to the alignment direction of the liquid crystal molecules.
• the transmission axis of the first polarizing plate 122 is set to be parallel to the alignment direction of the liquid crystal molecules.
• the phase difference of the second retardation plate 125 is set to a quarter wavelength, and its slow axis is arranged to be orthogonal to the slow axis of the first retardation plate 124.
• the reflection / transmission liquid crystal display panel manufactured as described above is connected to a driving device, and a backlight is disposed behind the device, thereby completing the reflection / transmission liquid crystal display device.
• the shape and arrangement of the pixel electrode 104 and the common electrode 105 are not limited to those shown in FIG. 141, and may be, for example, the shapes and arrangement shown in FIG. .
• the pixel electrode 104 shown in Fig. 15 has a small degree of curvature of the arc of the pixel electrode 104.
• the pixel electrode 104 shown in Fig. 141 has a comb shape. Not only between the area where the center of the teeth and the center of the comb teeth of the adjacent pixel electrode 104 are spread out, but also the area where the center of the comb teeth of the pixel electrode 104 and the center of the comb teeth of the adjacent pixel electrode 104 are narrowed together In the meantime, a reflection region R is provided. As shown in FIG.
• the reflection region R includes the comb teeth of the pixel electrode 104 including the region on the symmetry axis of the line-symmetric slit formed in the pixel electrode 104. This is included in the present invention because it is in a region where the comb teeth of adjacent pixel electrodes 104 face each other. According to such an arrangement, the distance between the pixel electrode 104 and the comb teeth of the pixel electrode 104 becomes wider as it goes to the root of the comb teeth, so that this region can be used as the reflection region R.
• the shape of the comb teeth (protrusions) in the comb-like pixel electrode 104 is not limited to the arc shape as shown in FIG. 14 and is, for example, the shape as shown in FIGS. You may do it.
• the pixel electrode 104 does not need to have a comb-teeth shape, and as shown in FIG. 16, the electrode 35 is an electrode 35 having a substantially elliptical slit surrounded by the pixel electrode 104. There may be.
• FIG. 17 is a schematic plan view showing the pixel electrode 104 and the common electrode 105 of the second embodiment.
• FIG. 17 (a) is a schematic plan view of the pixel electrode 104 and the common electrode 105
• (b) and (c) are schematic cross-sectional views of two types of broken lines GH shown in (a).
• the arrangement relationship between the pixel electrode 104 and the common electrode 105 is not limited to the form in which the pixel electrode 104 is formed in a layer closer to the liquid crystal layer 103 than the common electrode 105 as shown in FIG. 17
• the common electrode 105 is formed in the layer closer to the liquid crystal layer 103 than the pixel electrode 104! /.
• a shield electrode may be provided between the comb teeth of the pixel electrode 104 located in the reflection region R.
• FIG. 18 is a schematic diagram when the shield electrode 150 is provided between the pixel electrode 104 and the common electrode 105 of the second embodiment.
• FIG. 18 (a) is a schematic plan view
• FIG. 18 (b) is a schematic cross-sectional view taken along broken line GH shown in FIG. 18 (a).
• the strength of the electric field generated between the pixel electrode 104 and the common electrode 105 can be obtained by providing the shield electrode 150 in the reflection region R between the pixel electrode 104 and the common electrode 105.
• the shield electrode 150 is preferably grounded.
• the common electrode 105 may be formed in a comb shape, and the pixel electrode 104 may be formed on the entire pixel.
• the structure of the pixel electrode 104 and the structure of the common electrode 105 may be replaced with the above-described forms, or the present invention can achieve the effects of the present invention. it can.
• FIG. 1-1 is a schematic plan view of one pixel constituting the liquid crystal display device (IPS mode) of Embodiment 1.
• FIG. 1-2 is a schematic sectional view taken along broken line AB in FIG.
• FIG. 2 is a modification of Embodiment 1 (on the symmetry axis of a set of line-symmetric slits of pixel electrodes)
• FIG. 3 is a schematic plan view showing a linear comb tooth of a common electrode).
• FIG. 3 is a schematic plan view showing a modification of Embodiment 1 (a reflective region is formed even in a region where the center of the comb teeth of the pixel electrode and the center of the comb teeth of the common electrode are narrowed).
• FIG. 3 is a schematic plan view showing a linear comb tooth of a pixel electrode).
• FIG. 5 is a schematic view showing the positional relationship between a polarizing plate, a phase difference plate, and liquid crystal molecules when no voltage is applied in Embodiments 1 to 3.
• FIG. 6 is a schematic diagram showing the positional relationship between a polarizing plate, a retardation plate, and liquid crystal molecules in a reflective region when a voltage is applied in Embodiments 1 to 3.
• FIG. 7 is a schematic diagram showing the positional relationship between a polarizing plate, a phase difference plate, and liquid crystal molecules in a transmission region when a voltage is applied in Embodiments 1 to 3.
• FIG. 8 is a schematic plan view showing an electrode (a pixel electrode and / or a displacement of a common electrode or both) of a modification of the first embodiment (a shape in which a rectangular slit is bent once).
• FIG. 9 is a schematic plan view showing an electrode (a pixel electrode and / or a common electrode or both of them) of a modified example (a shape in which a rectangular slit is bent twice) of the first embodiment.
• ⁇ 10 A schematic plan view showing an electrode (a pixel electrode and / or a common electrode or both of them) of a modification of the first embodiment (a shape in which a rectangular slit is bent three times).
• FIG. 11 is a schematic plan view showing an electrode (either a pixel electrode or a common electrode or both) of a modified example (the slits meander) of the first embodiment.
• FIG. 12 is a schematic diagram showing the pixel electrode and the common electrode (the slit is arcuate) in the first embodiment.
• (A) is a schematic plan view
• (b), (c), and (d) are schematic cross-sectional views taken along the broken line CD in (a).
• FIG. 13 is a schematic plan view showing a modification of Embodiment 1 (having a shield electrode between a pixel electrode and a common electrode).
• (A) is a schematic plan view
• (b) is a schematic cross-sectional view taken along the broken line CD shown in (a).
• FIG. 14-1 is a schematic plan view of one pixel constituting the liquid crystal display device (FFS mode) of Embodiment 2.
• FIG. 14-2 is a schematic cross-sectional view taken along broken line EF shown in FIG. 14-1.
• FIG. 15 is a schematic plan view showing a modification of Embodiment 1 (a reflection region is formed even in a region where the center of the comb teeth of the pixel electrode and the center of the comb teeth of the adjacent pixel electrode are narrowed);
• FIG. 16 shows a modification of the second embodiment (the periphery of the slit is surrounded by electrodes).
• FIG. 6 is a schematic plan view showing whether the electrode and the common electrode are misaligned.
• FIG. 17 is a schematic diagram showing a pixel electrode and a common electrode (slits are arc-shaped) in Embodiment 2.
• (A) is a schematic plan view, and (b) and (c) are schematic cross-sectional views taken along broken line GH shown in (a).
• FIG. 18 is a schematic plan view showing a modification of Embodiment 2 (having a shield electrode between a pixel electrode and a common electrode).
• (A) is a schematic plan view
• (b) is a schematic cross-sectional view taken along broken line GH shown in (a).
• FIG. 19 is a schematic plan view showing a modification of Embodiment 2 (the common electrode is comb-like and the pixel electrode is formed on the entire pixel).

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• 2007
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